Iterative learning control design based on composite energy function with input saturation

In this work, iterative learning control (ILC) scheme is designed for a class of nonlinear system with the lumped uncertainty in the presence of input saturation. The analysis of convergence in iteration domain is on the basis of composite energy function (CEF), which incorporates the energy in time domain as well as the iteration domain. At the same time, input saturation is taken into consideration in the design of ILC scheme with the investigation on the properties of the saturation function. Through rigorous analysis, the convergence of the tracking error in iteration domain can be guaranteed under the input saturation provided the desired trajectory is realizable within the saturation bound.